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