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