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