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