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