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