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