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)(13,14,18,20)(15,22,19,27)(16,24,25,23)(17,26,28,21)(2,4)(5,7)(6,9)(8,11)(10,12)(13,15)(14,16)(17,24)(18,19)(20,25)(21,27)(22,26)(23,28) involution — undirected(7,11)(9,12)(13,16)(14,19)(15,20)(17,27)(18,25)(21,23)(22,28)(24,26) involution — undirected(7,11)(9,12)(15,19)(16,25)(22,27)(23,24) involution — undirected(6,10)(9,12)(14,20)(15,19)(21,26)(23,24) involution — undirectedA 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.