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