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