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