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