You don't need to see the contact icon to sync to your address book. However, check to see if it was moved to a folder on the phone. Sometimes with firmware updates, it will rearrange things. You cannot delete iOS icons, so it has to be there. Try a reset on the phone and see if that helps too.
Press down on the icon until it starts to wiggle. Then move it outside the folder onto the home screen. After doing that release. You should see it on the home screen, then press the home button to lock it in.