This is a slight modification on the layout Casio did for the Privia PX-5S, which can be found in this blog article. Casio says:
We just couldn’t help ourselves. MIDI Designer is such an amazing program that we couldn’t resist making layouts which control the PX-5S. We’ve done layouts for both the iPhone (iPod touch) and the iPad...These layouts gives you control over Zone volume, filters, effects mix, and even some Hex Layer control allowing you to use the physical knobs and sliders on the PX-5S for other things.
iPad Layout... download here.

iPhone layout, download here.

