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