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