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