So if I understand correctly you are looking for a gesture to quickly switch between open desktop applications. Desktop does not support gesture based input so there isn't a way to swipe from the side to cycle through desktop applications. About the closest thing you can do is to use an app in the side bar. Then shifting that app to the main app and placing the desktop in the side bar you will get a list of all the open desktop windows in the side bar. Touching the one you want will make that widow open and move desktop to the main part of the screen.
So in practice it would go some thing like this. Open desktop and all windows necessary. Open secondary app and place it in right or left side bar. Swipe left or right (depending on which side you placed the app) to make the desktop the sidebar app. Then touch the window you want to switch to. Lather, rinse, repeat.
Of course simply using the keyboard is going to be the quickest option to switch between open windows even if you had a direct gesture. Pressing two keys repeatedly is quicker that reaching up and swiping multiple times.