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