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