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