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