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