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