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