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