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