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