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