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