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