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