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