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