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