I am sure there is no way to permanently turn it off (as in a setting that makes it disappear), but there is a way to make it temporarily switch into something else.
On the bottom left, there should be a small square generic map icon. Clicking on that will make it turn into a real "mini map" showing your drone's location, amongst other trajectories. When the mini map is showing, the orientation information that would normally show up on the bottom center of the screen will disappear until you have minimized the "mini map" on the bottom left (when you do so, it turns back into a small square map icon).
It basically works like this: you can either see the "mini map" or the orientation, but never both at the same time.