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