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