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