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