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