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