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