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