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