I don't think you can because a Photoshop file (PSD) with layers will be flattened when you open up in Photoshop Touch.
I prepared a Photoshop file with one layer of image, one layer of text over a background using Photoshop CS6 on my Mac Pro and upload the PSD file onto Creative Cloud. I then open this file in Photoshop Touch (on iPad) but it comes out as a single flat layer merging all three layers. Hope this helps.
Below: 3 layers in Photoshop CS6 (with one layer of text)
Below: Flattened into one layer in Photoshop Touch..