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