Two choices:
1. Apply for an H1 visa to come back and your status will continue to be H1.
2. Use AP to come back and continue to work with your current employer and need to do nothing. Your status will be AOS and your H1 status can be re-instated by doing H1 renewal, transfer or going out of U.S. to get an H1 visa in the future.
Both choices will not affect your I-485.