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