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