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