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