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