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