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