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