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