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