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