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