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