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