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