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