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