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