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