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