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