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