Is there a Sanskrit (not Pali) version of the Five Precepts? Can anyone provide me a Sanskrit (not Pali) translation of the Five Precepts?
I believe that the link that follows would be your one of your best options for tracking down a Sanskrit version of the Five Precepts. It indicated that this is to be found in the liturgy. Get in touch with them and see if they can provide more information.

http://nalandatranslation.org/offerings/notes-on-the-daily-chants/commentaries/ritual-for-taking-the-five-precepts/