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