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