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