XTrack seems to work. I've been playing with it now for awhile. And best yet is that it's free along with working with Mac OS
There is one other that I discovered but I wasn't able to get the free trial to work myself. But just for your info here ya go but it comes with my warning. http://www.haddonsoftware.com/howtobuy.html
I use RailModeller Pro for macOS, available in the AppStore. Very slick and Mac-like with an excellent, easy-to-learn UI. Over 250 track-libraries in all scales for all major model railroad brands, even slot cars. Full Kato Unitrack and Unitram track libraries. Supports Photoshop-like layers. Mature program and very stable. Free trial version available (limited to 50 track-pieces). The image below is a Kato Unitrack layout, output from RailModeller Pro: