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