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