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