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