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