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