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