That's a good question. My first thought is that you'll have to hand draw it in an isometric view (3/4 top down) or something more icon-like so that you can get all of the descriptive lines in there. This goes in stark contrast to the mountain style used on Mercator maps (fuzzy caterpillars). I'll look through my collection to see if there's anything there that can be co-opted but I don't remember anything off the top of my head. Maybe someone else has a link.