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