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