give some method to unroot this phone number
PS I'm from Latin America
you will need to flash a stock ROM (or if you made a stock back-up (image backup) then just restore from your recovery menu)
then go to your SU and go to settings>unroot
once that is done you will need to flash the stock Boot.img (this part can be difficult) Use an all-in-one tool kit for the HTC one S
then everything should be done and completely stock.
PS... Look on XDA-developers.com for more information. (this is also where you can find the Stock ROM/Boot.img/and Tool kit) <-- be sure you are looking in the HTC one S forum>development
Good luck