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