How do i connect an air compressor's 5 wires to a 3 prong 220 dryer plug?
You need to look at the motor plate to see what they want you to do.   

Typically with a 120/240 switchable motor, you are jumpering two sections of the motor into series or parallel.  So for 120V you might make connections hot1-A-C and B-D-neutral, and for 220V you wire hot1-A, B-C, and D-hot2.   It may be more complicated than that if there's a start capacitor or start winding involved.   

Point being you must make those connections as the factory instructs, and those instructions will be particular to the motor, and should be on the motor plate.