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