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