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)(21,24)(22,23)(25,26,30,33)(27,31,35,29)(28,36,39,32)(34,38,37,40)(1,2,4,5)(3,6,7,8)(9,11,15,13)(10,16,19,20)(12,21,18,23)(14,24,17,22)(25,27)(26,29)(28,34)(30,35)(31,33)(32,38)(36,40)(37,39)(11,13)(16,20)(21,23)(22,24)(25,27,30,35)(26,29,33,31)(28,37,39,34)(32,40,36,38)(9,12,15,18)(10,17,19,14)(11,21,13,23)(16,22,20,24)(25,27)(26,31)(28,34)(29,33)(30,35)(32,40)(36,38)(37,39)(9,13,15,11)(10,16,19,20)(12,23,18,21)(14,24,17,22)(25,28)(26,32)(27,34)(29,38)(30,39)(31,40)(33,36)(35,37)(1,3,4,7)(2,6,5,8)(9,14,15,17)(10,18,19,12)(11,22,13,24)(16,21,20,23)(25,29,30,31)(26,27,33,35)(28,38,39,40)(32,34,36,37)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.