is there a way to visualize the pipeline such that this step is “stuck” in executing?

Yes there is, the pipelline plot (see plots section on the Pipeline Task, will show the current state of the pipeline.
But I have a feeling you have something else in mind?
Maybe add Tag on the pipeline Task itself (then remove it when it continues) ?
I'm assuming you need something that is quite prominent in the UI, so someone knows ?
(BTW I would think of integrating it with the slack monitor, to push a p=message to users that the pipeline is waiting for human interaction), wdyt ?