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