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