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