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