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