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