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