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