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