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