It is not that difficult to plan for a "less ugly" robot.
Have a plan for mounting your electronics. For example, put your motor controllers all neatly in a line or a grid, orienting the same way. Run your cables in straight "streets and alleys", bundling them up wherever you can. Hide them inside channel if you can do it. This will look pretty and help avoid the rat's nest that is so difficult to debug (you know you've been there).
Use systematic wire colors (some of that is obvious, like red/black and green/yellow for CAN) but you can also sheath them in shrink wrap or flexible conduit tubing that is color coded.
When swiss-cheesing or making cutouts for wires or whatever, do a little measuring and make holes symmetrical, aligned, all the same size and spaced out evenly, instead of just drilling or cutting wherever.
Things that look good: symmetry, clean lines, clean angles, repetition of items with the same size and shape.
Also: mecanum wheels are ugly 