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