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