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