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