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