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