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