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