It's acrylic (I'm guessing) so be very careful to lift off, or roll off dust and dirt with a well-washed cotton towel. I use a *natural* bristle paint brush (with tape around metal parts) and flick dirt into a nearby vacuum. Dang acrylic stuff is trouble since it gets static charge so easily which attracts more dust, so a wipe with damp cloth should follow. Dampness discharges charge added by vacuum and brush.
Oh, another impt point: I
avoid cleaning it as much as possible since everytime you clean it, unless you're NASA, you cause slight, yet cumulative damage to it.