...That's considered maladaptive?? o_O I had no idea...
Well...as someone who apparently also has this...it's not really that big a deal, I don't think? ^^; It just feels like having the TV or radio on 24/7.
In my case, the TV is voluntary-- stuff I particularly want to think about, like my comic scripts and novels, and animations I wish I could do. I can easily turn this on or off...although it will turn itself back on repeatedly if it's an idea I'm really invested in, something that's new or particularly cool (i.e. I actually want to write it down to work on later). I guess this is definitely kinda disruptive...but at its worst, I can usually manage by listening to something IRL to distract myself from my own brain, like a podcast or sthg.
The radio is involuntary-- it just plays in the background of my mind, any song (or a short snippet of a song, or sometimes a spoken quote) that my brain can conjure up at the time. Although it can get very repetitive, it's only annoying if I think about it, like how you don't notice the feeling of your clothes on your skin until you start actively thinking about it.
I don't think there's any trickedy-trick to 'portraying' something like this; to me it doesn't feel any different from having regular thoughts...there's just more of them. ^^; Like, the way people usually portray daydreams in media, with the world dissolving into a fantasy-land, or the things they're thinking about popping up in their vision while they're supposed to be focused on other things...feels fairly accurate already. :T
Personally, my daydreams just look like a transparent screen over my field of vision. But if I were to draw it in an artsier way, I guess I'd do something like: I'm having a conversation with my boss, and there are anime girls fighting in the background, doing parkour all over the countertops and interacting with the setting as if they're actually there. And I'm just conversing normally, more or less paying attention, but also sneaking glances at 'em every once in a while. ^^