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