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