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