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