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