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