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