First of all, there are no infinite combos in the cube. The cube is balanced around the 10 guilds with 5 multicolored cards for each guild. There is one card for each tricolour combination that is trying to combine the themes of the three overlapping guilds.
There are 4 manafixing lands per guild, but no fetchlands, so going 3+ colours is possible, but at a cost.
The themes of the guilds are as follows:

Azorius/ : Control
Use counterspells and carddraw from blue with efficient removal and mass removals from white to stabilise and finish the opponent with a big threat like dream trawler

Simic/ : Ramp
Use greens ramp to get going faster and slam big haymakers to win the game. The blue mostly adds consistency with card draw/selection and it gives you access to some utility creatures. This deck can splash very easily to other colours for more finishers.

Dimir : creature based control
Get your 2-for-1s with your creatures and big spells. This is more of an tap out control deck than azorius. This is also most likely the best God-Pharaoh's Gift deck in the cube.

Orzhov Aristocrats
You need 3 pieces for this deck: sacrifice fodder (bloodghast, lingering souls), a sac outlet (cartel aristocrat, woe strider) and a payoff (cruel celebrant, blood artist). The rest of the deck is some removal and then you'll get there. Mass removal can work like a sac outlet in a pinch

Rakdos aggressive sacrifice
At base, this is an aggro deck, that wants to kill fast. Then on top to finish the game, you use a similar suite of sacrifice synergies to finish the opponent. Additionally you get "threaten" effects to bolster the strategy for very cheap "steal and sac" synergies.

Gruul : zoo/ atarka red
This deck is very aggressive and wants to bash heads in with efficient, cheap creatures like experiment one, voltaic brawler and goblin rabblemaster. Your top end is usually at 4 Mana with bloodraid elf and polukranos

Boros : go wide Aggro:
This is deck wants to go wide and then buff all your creatures with anthems and Bushwhacker effects.

Izzet : Spells matter Aggro
This deck is very explosive. You either go wide with young pyromancer and their friends or go tall with the prowess creatures. This deck depends on cheap instants and sorceries to trigger your enablers.

Selesnya : blink/flicker
This deck abuses enter the battlefield effects of creatures and triggers them again when exiling it and bringing it back. You haven't truly lived until you flickered a thragtusk the same turn you play it

Golgari : Creature toolbox:
This is by far the most difficult deck to draft in the cube. This deck is a slow midrange deck, that wants to tutor up the exakt creatures it needs at the moment with spells like green sun's zenith, chord of calling, fiend artisan. The second way of tutoring is by using birthing pod (and Vivien). This puts your deck under a tight deck building restriction and you have to remember your curve (and what cards you already played and can't find anymore), but if you manage this you have a very versatile deck, that can grind through almost everything. Creatures with enter the battlefield effects or dies trigger work especially well in this. One additional note: you can find grist, the hunger tide from any Creature tutor, that finds a 3 MV creature.