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