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