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