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