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