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