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