Here are some possibilities for control of an air compressor with 
a simple pressure switch, on/off button and a motor starter 
(often referred to as a magnetic starter).

There are two types of on/off buttons…one is separate buttons 
which require the use of a control relay.  A maintained button 
that has a mechanical detent or rocker linkage is more of a 
maintained selector switch, hence drawn that way in the lower 
circuit.