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