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