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