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