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