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