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