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