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