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