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