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