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