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