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