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