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