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