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