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)(11,16)(12,17)(13,21)(14,15)(18,22)(19,20)(23,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,39)(36,38)(37,40)(1,3,5,8)(2,6,4,7)(10,15)(12,16)(18,21)(20,23)(25,26,30,29)(27,31,33,35)(28,36,38,32)(34,40,37,39)(1,4,5,2)(3,7,8,6)(10,15)(11,17)(18,21)(19,24)(26,29)(27,33)(32,36)(34,37)(9,11,14,17)(10,16,15,12)(13,19,22,24)(18,23,21,20)(25,27,30,33)(26,31,29,35)(28,37,38,34)(32,40,36,39)(9,12,14,16)(10,17,15,11)(13,20,22,23)(18,24,21,19)(25,28,30,38)(26,32,29,36)(27,34,33,37)(31,39,35,40)(9,13,14,22)(10,18,15,21)(11,19,17,24)(12,20,16,23)(25,29,30,26)(27,35,33,31)(28,36,38,32)(34,40,37,39)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.