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