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