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