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