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