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