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