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