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