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