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