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