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