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