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