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