Can light cover to soften harsh led bulbs
Not sure of covers, as the cans need to open for ventilation to avoid overheating the led from long operating periods.
Things you can do to remove the harshness

Select warm white colour(3700k) led bulbs if you dont like daylight (6500k)  
Get bulbs with pearl coating (led bulbs come in two variants clear
and pearl(diffused light) , if you can replace the bulb (not sure on your fitting , some are hard wired vs some are socketed)
Get different brand of led light (some leds have a broader led lens to spread the light)
Use a universal dimmer to control brightness of leds