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