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