A sure way to get her to get sexified? Take better care of yourself (mentally and physically). Partner's are always pinging their significant other to ensure things are status quo. IF you implement some change into the mix, particularly for yourself, the partner won't want to 'fall behind' or disappoint by doing nothing (the expectation for change this way is implicit - no need to have conversations).

Plainly put, start working out, dress more nicely etc.. Nothing worse for a woman than to feel like the odd 'man' out with her partner - feel she's not worthy (e.g., lesser attractive in your case).