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