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