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