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