Saturn's apparent magnitude as watched from Uranus is +3.228. Jupiter's orbit is further in towards the sun. Can we expect its apparent magnitude to be greater than Saturn's, or is it in fact lesser? (Less is brighter in the world of apparent magnitudes apparently)
I started Stellarium on my computer and pressed F6 to bring up the "Location" window.
Then I changed the planet to "Uranus", and marvelled at the view of the many rings and many moons from the planet's "surface"
For convenience I clicked the buttons to remove the ground and the atmosphere. then I found and clicked on Saturn. It had a magnitude of 3.74. I then pressed F5 to get a time window and stepped one month at a time while watching the change in Saturn's brightness. The maximum I could get was +3.55 (in 2042) though it is believable that it could get brighter at a more favourable elongation in it's elliptical orbit. I also noted that as Saturn passes in front of the sun, its magnitude gets much less, well below naked eye.
I then repeated with Jupiter. It has a maximum brightness of +1.55 (in about 2031) but again, it is believable that it would be brighter at a more favourable elongation.
At its brightest, Jupiter is a lot brighter than Saturn when viewed from Uranus.