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