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)(11,16)(12,18)(13,17)(14,19)(15,20)(21,22)(23,24)(25,26,31,36)(27,32,30,35)(28,34,29,33)(37,40,38,39)(1,3,5,6)(2,4,7,8)(9,11,15,13)(10,16,20,17)(12,23,19,21)(14,22,18,24)(25,27,31,30)(26,32,36,35)(28,38,29,37)(33,40,34,39)(9,11,15,13)(10,17,20,16)(12,21,19,23)(14,22,18,24)(25,28,31,29)(26,33,36,34)(27,37,30,38)(32,39,35,40)(1,2)(3,4)(5,7)(6,8)(9,12,15,19)(10,18,20,14)(11,21,13,23)(16,22,17,24)(25,26)(27,35)(28,33)(29,34)(30,32)(31,36)(37,40)(38,39)(1,2)(3,4)(5,7)(6,8)(9,13,15,11)(10,16,20,17)(12,23,19,21)(14,24,18,22)(25,29,31,28)(26,34,36,33)(27,37,30,38)(32,39,35,40)(1,4)(2,6)(3,7)(5,8)(9,14,15,18)(10,19,20,12)(11,22,13,24)(16,21,17,23)(25,30,31,27)(26,35,36,32)(28,38,29,37)(33,40,34,39)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.