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