How can I shade my garage door opener keypad?
An easy visually pleasing solution would be to visit your local hardware or electronics store and look for a weather resistant box with a lid similar to the following (2-Gang Rectangle Plastic Electrical Box shown bellow) :

I couldn't find any dimensions but something of this nature will protect the keypad from the elements. It will require you to do some custom fitting ie: removing the keypad, mounting the box, running the ribbon through and then securing the keypad, but will definitely do the job.

Here is the PDF for the model you have provided that should help you with disconnecting / reconnecting the ribbon cable aka Signal Tail.

(source: imageg.net)