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