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