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