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