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