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