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