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