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