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