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