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