One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,3)(5,6)(7,9)(8,10)(11,12)(13,14,17,23,18,24,19,25)(15,21,28,22,26,20,16,27)(2,3)(5,6)(7,11)(8,10)(9,12)(13,15)(14,20)(16,19)(17,28)(18,26)(21,24)(22,25)(23,27) involution — undirected(5,7)(6,9)(8,12)(10,11)(13,16)(14,21)(15,19)(17,26)(18,28)(20,24)(22,25)(23,27) involution — undirected(1,3,4,2)(7,12)(9,11)(13,16)(14,22)(15,17)(18,28)(19,26)(20,23)(21,25)(24,27)(6,10)(9,11)(13,17,18,19)(14,23,24,25)(15,16,26,28)(20,22,21,27)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.