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)(11,19,22,15)(12,23)(13,17)(14,18)(16,25)(20,28,35,33)(21,31,26,29)(24,36)(27,32)(30,38)(34,39,37,40)(9,11,14,22)(10,15,18,19)(12,20,25,35)(13,26,27,21)(16,28,23,33)(17,31,32,29)(24,37,38,34)(30,40,36,39)(2,5)(3,7)(9,12)(10,16,18,23)(11,20)(13,24)(14,25)(15,28,19,33)(17,30,32,36)(21,34)(22,35)(26,37)(27,38)(29,39,31,40)(9,13,14,27)(10,17,18,32)(11,21,22,26)(12,24,25,38)(15,29,19,31)(16,30,23,36)(20,34,35,37)(28,39,33,40)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.