Where is the Starter / Anti-Theft Relay located?

That is where it should be, if it's still there. Many have been removed, even though it is the least troublesome part of the system, and still won't allow it to run because the PCM doesn't get the fuel enable pulses to turn on the injection system. I've found them by looking for the wires that go to them. You can see those in the wiring diagram. I would start by verifying the system operates, turn the key on then jump the purple wire (start) terminal to battery power, if it's only the relay the car should start and run. If it just cranks but doesn't start it isn't just the relay.