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)(11,14)(12,17)(13,18)(15,19)(16,21)(20,22)(23,24)(25,26)(27,34)(28,29)(30,31)(32,35)(33,38)(36,40)(37,39) involution — undirected(2,5)(6,7)(10,11)(12,19)(16,18)(20,24)(26,31)(28,33)(32,34)(36,39) involution — undirected(1,2)(3,6)(4,5)(7,8)(10,11)(15,17)(16,18)(22,23)(27,35)(32,34)(36,39)(37,40) involution — undirected(1,3)(2,6)(4,8)(5,7)(9,11,14,10)(12,17,19,15)(13,18,21,16)(20,23,24,22)(25,27,30,35)(26,32,31,34)(28,36,33,39)(29,37,38,40)(9,12,14,19)(10,15,11,17)(13,20,21,24)(16,22,18,23)(25,28,30,33)(26,29,31,38)(27,36,35,39)(32,37,34,40)(9,13,14,21)(10,16,11,18)(12,20,19,24)(15,22,17,23)(25,29)(26,33)(27,37)(28,31)(30,38)(32,39)(34,36)(35,40)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.