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