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