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