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