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