So your cloud of Cessnas could conceivably carry 60 Stingers. How will they detect a fighter flying at 30K? A 172 can only get to about 15K in perfect conditions. It flies at like 100mph compared to a Mach 2 F-35.
Again, short of being a suicide bomber trying to kill an F-35 on the ramp, this idea is ludicrous.
To create a drone capable of threatening an F-35 requires creating something very similarly capable in all ways but without the pilot. This may exist one day but it isn't going to come at a discount.
Those missiles are not cheap, and it would be unlikely for cheap Cessnas to get in range of an F-35. At long range the F-35 is difficult to observe by sensors that fit inside a Cessna.
I believe it is possible to shoot down low-radar-crossection aircraft if the missiles are spotted/guided by other sensor networks, but that is not easy, cheap, or mobile. And land based radars are sitting ducks.