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)(11,16)(12,14)(13,21)(15,17)(18,22)(19,23)(20,24)(25,26,31,29)(27,34,37,32)(28,38,30,33)(35,39,36,40)(1,3,5,8)(2,6,4,7)(9,11,15,12)(10,16,17,14)(13,20,22,19)(18,23,21,24)(25,27)(26,32)(28,35)(29,34)(30,36)(31,37)(33,39)(38,40)(1,2,5,4)(3,6,8,7)(10,17)(11,12)(13,22)(23,24)(25,28,31,30)(26,33,29,38)(27,35,37,36)(32,39,34,40)(9,12,15,11)(10,14,17,16)(13,20,22,19)(18,23,21,24)(25,29,31,26)(27,34,37,32)(28,33,30,38)(35,39,36,40)(9,13)(10,18)(11,19)(12,20)(14,23)(15,22)(16,24)(17,21)(25,27)(26,32)(28,35)(29,34)(30,36)(31,37)(33,39)(38,40) involution — undirected(1,4,5,2)(3,7,8,6)(9,14)(10,11)(12,17)(13,23)(15,16)(18,19)(20,21)(22,24)(25,30,31,28)(26,33,29,38)(27,36,37,35)(32,39,34,40)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.