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