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