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