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