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