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