It appears that your site is using another mobile theme (WP Touch). Graphene Mobile Neo is designed to work alongside your desktop theme (which is Graphene), but not a second mobile theme.
On top of that, Graphene Mobile Neo need not be activated in order for it to work. The bundled helper plugin takes care of loading the theme when necessary. This is reflected in the theme’s [url=https://forum.graphene-theme.com/graphene-mobile-neo/installation-instructions/]Installation Instructions[/url].
If you need assistance with installing and setting up Graphene Mobile Neo, we are available to help at no extra charge.