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