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