From the homescreen, go to the App Drawer.
There you click on the menu and then "Apex settings". Then click on "Drawer settings" and "Drawer background transparency"
Push the slider to 82%. Of course you can also set more or less percent. Just try it until you like it. When you find a setting that you like, just press on "Ok. That's it.
That's it. You now have a transparent Drawer background.
