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