Mount a 20 amp switch in a weather proof enclosure (metal dust will get inside anything else) and wire it to the motor, with the power cord going to the wall plate. Make sure the circuit is rated for that kind of load. You really should have a dedicated outlet wired in 10 Ga. wire right to the breaker box. If it is possible, you should consider wiring the motor and the outlet for 220. It draws only half the current per leg (same total wattage).
Stacy