You would have to use wifi tether on the evo, which you have to pay 30 bucks a month to sprint, or root. Or you can hook up usb to your computer and tether with pdanet, then connect an ethernet from computer to ps3 and bridge the two connections.
Either way, you arent going to be able to play any fast paced games online using the evo as a gateway. Even if you have a full signal, the ping times for 3g and 4g are horrible for online gaming.