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)(26,32)(27,34)(29,30)(33,40)(35,36)(37,38)(2,5)(6,8)(9,11)(10,14)(12,18)(13,17)(15,22)(16,21)(19,24)(20,23)(25,26,30,32,31,34,29,27)(28,36,37,35,39,33,38,40)(1,3,4,7)(2,6,5,8)(11,17)(14,21)(18,23)(22,24)(25,27,30,26,31,32,29,34)(28,35,37,33,39,40,38,36)(11,17)(14,21)(18,23)(22,24)(25,28)(26,33)(27,35)(29,38)(30,37)(31,39)(32,40)(34,36) involution — undirected(9,12,13,20)(10,15,16,19)(11,18,17,23)(14,22,21,24)(25,29,31,30)(26,27,34,32)(28,37,39,38)(33,40,36,35)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.