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