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