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