One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(9,10,15,20,34,24,17,26,14,19,16,21,13,11,22,25)(12,27,31,23,29,40,36,37,30,38,32,39,33,28,35,18)(2,4)(5,6)(7,8)(9,11,15,25,34,10,17,20,14,24,16,26,13,19,22,21)(12,28,31,18,29,27,36,23,30,40,32,37,33,38,35,39)(6,8)(9,12,14,30)(10,18,19,37)(11,23,24,39)(13,29,34,33)(15,35,16,36)(17,32,22,31)(20,28,21,40)(25,27,26,38)(2,4)(9,13,14,34)(10,11,19,24)(12,29,30,33)(15,22,16,17)(18,23,37,39)(20,25,21,26)(27,40,38,28)(31,36,32,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.