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