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