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