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