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