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