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