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