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