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