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