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