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