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