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)(13,14,19,27,18,20,17,23)(15,24,25,21,16,22,26,28)(1,2)(3,4)(5,6)(7,11)(8,10)(9,12)(14,20)(21,28)(22,24)(23,27) involution — undirected(5,7,8,12)(6,9,10,11)(13,15,18,16)(14,21,20,28)(17,25,19,26)(22,27,24,23)(2,4)(7,12)(9,11)(13,16,18,15)(14,22,20,24)(17,25,19,26)(21,27,28,23)(6,10)(9,11)(13,17,18,19)(14,23,20,27)(15,25,16,26)(21,22,28,24)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.