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