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