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