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