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