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