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