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