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