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