One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(9,10,14,19,15,22,13,20,16,21,12,18,31,37,30,38)(11,23,26,35,27,33,25,34,28,40,24,39,32,36,29,17)(2,4)(5,6)(7,8)(9,11,16,28)(10,17)(12,29,14,25)(13,26,30,24)(15,32,31,27)(18,36)(19,33)(20,23)(21,34)(22,39)(35,37)(38,40)(2,4)(6,8)(10,18,21,19)(12,30)(13,14)(15,31)(17,33,34,36)(20,37,38,22)(23,39,40,35)(24,29)(25,26)(27,32)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.