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