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