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