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