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