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