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