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