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