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