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