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