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