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