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