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