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