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