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