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