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