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