If it's only a transformer, you can get an industrial coiled cord power cable from a supplier like Grainger or any Industrial Electrical Supplier. They flex nicely and look good. The least expensive ones have 3 conductors (Black-White-Green) but I have seen up to 6 conductors to use with switch boxes or to power industrial automation items that move. Amazon even lists a bunch.
Despite all the talk on the forum, I doubt that based upon the size of your layout, you would need any more than 16 gauge wire in the cord. Consider the size of wire used by MTH in it's banana jack cables.
Lad