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