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