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