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