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