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