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