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