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