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