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