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