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