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