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