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