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