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