First of all, don't bother with lings or hydras. Reavers will rape you and it'll cost you soo much. They give you enough time to build straight up to Guardian, so do it. Make sure you start mining gas ASAP because that'll be your limiting factor for Guardian production. When you have 8 you can start attacking while you build some Muta's you'll need for clearing Yellow.
Eliminate Teal in the middle first and claim his 2 bases. Ignore his cannons leftover in the east and kill his cannons on the cliff above Yellow's base. From there attack Yellow. Make sure you have at least 12 - 24 Mutas and 6-12 Scourges. And when Scouts appear drop 1-2 Scourges on them and finish. 3 for Carriers.
Ignore Yellow on the east for now just clear to the middle so you can build another base with a lot of minerals south to your main.
Then start destroying Orange's base starting southwest. Make sure you kill the arbiters with scourges, so they can freeze you only once. If you're fast enough he won't ever rebuild them.
Be sure to move slowly and use your range over cliffs. At the beginning of your assault he'll send a lot of units, so make sure the first wave is dead before you move further into his base south and then east.
Be careful about Templars: when you see one, attack with Mutas but fly through the storm, so he kills himself. Morph critically wounded Mutas into Guardians to fully heal them.
Produce more Mutas all the time and send them to replenish your losses and have 1 group of Mutas and a group of Scourges ready to defend your bases.
The orange base should be mostly destroyed by the 45 Minute mark and the rest is cleanup so you can safely send your drone to the Khaydarin Crystal formation. About the time when your drone is done mining you should be done with all Yellow's and Teal's remnants.
This strategy relies on speed so the enemy bases don't have much time to retaliate or build up a sizeable defense force.
And to retain momentum you'll need some basic micro skills, like using Guardians from cliffs, always having your units spread a bit to avoid Storms and Reavers and sending just the right amount of Scourges against the strong Toss air units.