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