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)(25,26,32,34)(27,28,30,31)(29,33,38,40)(35,36,37,39)(1,3,5,8)(2,6,7,4)(9,10)(11,17)(12,16)(13,14)(15,18)(19,23)(20,21)(22,24)(25,27)(26,28)(29,37)(30,32)(31,34)(33,39)(35,38)(36,40)(1,3)(2,4)(5,8)(6,7)(11,18)(15,17)(19,24)(22,23)(25,28,32,31)(26,27,34,30)(29,36,38,39)(33,35,40,37)(1,4)(2,3)(5,6)(7,8)(9,10)(11,15)(12,20)(13,14)(16,21)(17,18)(19,23)(22,24)(25,29)(26,33)(27,35)(28,36)(30,37)(31,39)(32,38)(34,40) involution — undirected(9,11,13,18)(10,15,14,17)(12,19,21,24)(16,22,20,23)(25,30,32,27)(26,28,34,31)(29,37,38,35)(33,36,40,39)(9,12)(10,16)(11,19)(13,21)(14,20)(15,22)(17,23)(18,24)(25,31,32,28)(26,27,34,30)(29,36,38,39)(33,37,40,35)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.