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