I forgot where a certain groups setting is...?
Using Jamroom
I just checked in your database, and you have customized the item_index.tpl file for the groups module and have purposefully excluded the button:
{*** ADDED: Only allow admins to create groups ***}
{if jrUser_is_admin()}
{jrCore_item_index_buttons module="jrGroup" profile_id=$_profile_id}
{/if}
So you'll want to fix that if you want it to show for your users.
