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