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