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