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