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