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