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