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