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