No. Only admins can access the CP. If you don't want them called Admins, you CAN create another group name, change Admins to a hidden group, and they (and you) will show that way - but they still have to be assigned as admins in the CP. For example, my group name shows as "Founder-Admin" and my assistant shows as "Assistant Admin". Both are admin group members with different group names.
Saurus explained it pretty well, there isn't really much to add. You have to add them to the admin usergroup if you want them to see the admin panel, so the answer to your question is no.