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