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