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