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