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