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