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