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