My guess is we'll see examples drawn both ways, but when characters in these two universes use tk, from teh character's point of view, is the force being exerted invisible. Like in star wars, or heroes the object just moves. In the comics, there is often some kind of colored cloud around the object getting levitated, instead of like swish lines, or however else you'd draw invisible. Does mutant/metahuman tk show to the naked eye, or is that just for our benefit?
Absolutely for the readers.
On a side note, heat vision is also invisible! In No Man's Land, Superman shows up to help out...Batman can only see his heat vision through the use of infrared lenses.
except for certain specific TK's like you know biotics, tactile telekinesis, etc....