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