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