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