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