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