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