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