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