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