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