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