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