Sure you can.
What you can do is, remove the fuel pump relay. Then on the secondary side of the relay socket, run two wires from the relay socket to a switch on the dash. The secondary side of the relay is always hot.
Size the switch and wires to handle ten amps.
And if possible, install a switch that lights up when it's turned on. That way, it's less likely you'll forget to turn off the fuel pump when you stop the vehicle.